Problem: $ { \left[\begin{array}{rr}{-1} & {-1} \\ {3} & {0} \\ {0} & {0}\end{array}\right]-\left[\begin{array}{rr}{-2} & {1} \\ {-2} & {-2} \\ {0} & {1}\end{array}\right] = {?} } $
Solution: To find the difference of two matrices, subtract the corresponding items between each matrix. ${\left[\begin{array}{rr}{-1}-{-2} & {-1}-{1} \\ {3}-{-2} & {0}-{-2} \\ {0}-{0} & {0}-{1}\end{array}\right]}$ Now, simplify: ${\left[\begin{array}{rr}{1} & {-2} \\ {5} & {2} \\ {0} & {-1}\end{array}\right]}$